The present invention relates generally to machines used in the graphic arts industry which register a paperboard sheet and feed it to the input of another machine where it may be printed, folded, coated, die cut or separated. The present invention may be made a part of such other machines, or a succession of such other machines, or it may be separate but placed adjacent to such other machine which requires sheets to be registered. More specifically, the present invention relates to a machine which receives sheets of paperboard or other material from another machine of which a die cutter would be one example where the sheets are placed or fall with various angles of skew, moves them to a side register where they are registered and then drives them out of this machine and onto the input device of a following machine. Such a following machine, for example, may be the applicants separating machine disclosed in U.S. Pat. No. 4,000,686.
The prior art includes U.S. Pat. No. 3,807,610 and U.S. Pat. No. 3,670,937, both issued to Arthur R. Mueller Jr., as well as applicants U.S. Pat. No. 4,000,686 referred to above. These patents disclose separating machines wherein die cut cards are separated from the paperboard scrap from which they were cut but also include in their input or feeder end some manner of registering device. V-belt feeders as well as flat belt feeders have been used. Feeders which stop while the sheet falls thereto and start thereafter have appeared in the prior art. All such devices depend on a side register guide on the following machine which moves the sheet slowly towards the guide where it is registered. Sheets from a die cutter fall onto a conveyor and in falling often tend to float down rather than dropping down in perfect position. Consequently, in the prior art, a register guide and feeder required a long section of angled conveyor rolls or belts so that the sheet was not turned too quickly resulting in a folded leading edge. With these angle conveyor rolls there is an angle of skew beyond which a sheet will not register but will move forward and into the separator retaining the angle of skew and resulting in a jam-up which loses valuable time and production. In the prior art, the side guide means of registering the sheet are suitable for specific processes only, i.e., where the material is handled in a continuous process such as taught by Mueller U.S. Pat. No. 3,807,610 and U.S. Pat. No. 3,670,937. When the process requires intermittent motion on the part of the transport means (start, stop, dwell), cycle time becomes critical and the sheet of material must be presented to the transport means with the gripper edge re-registered. Otherwise, the subsequent processing would be too slow to justify further mechanization. For example: A 25".times.38" sheet (popular size) with the original side guide edge (25") presented to the transport means would require 52 percent more time in traverse than if the original gripper edge were presented. Further, as a practical matter, sheets of material cut exactly square are not commercially available therefore when registering the side guide edge only, any error in out of squareness will be magnified by the ratio of length to width, resulting in significantly greater error in register of the original leading (gripper) edge. The prior art registering devices cannot re-register the original leading (gripper) edge of the sheet.
The present invention side registers a sheet rapidly and reliably, without folding the leading edge, in a space smaller than that required by the prior art devices. The reduced size of the feeder section of separating and other machines results in a reduced cost in addition to a saving in space. The rapid and reliable side registering of a sheet when skewed at substantial angles in either direction is the result of a unique combination of friction coated parallel driven conveyor rolls, a plurality of balls in rolling contact with a final uncoated driven conveyor roll, a throated fixed side register guide, and a plurality of tapered friction complementary pairs of driven side register forwarding rolls.
The present invention may be used in a complete, integrated carton line placed after the printing press and before a die cutter and a second pre-registering feeder machine placed after the die cutter and before the separating machine.
The present invention may also be used in a Blister Card line with one machine placed after the printing press and before the coating conveyor line, another pre-registering feeder machine placed after the coating line and before the die cutter and a third pre-registering feeder after the die cutter and before the stripping machine.